Reinforced vulcanized fiber backing belt



Aug. 18, 1942. H. B. FAY 2,293,246

REINFORCED VULCANIZED FIBER BACKING BELT Filed Aug. 26, 1941 FIGI.

INVENTOR. HORACE B. FAY. BY I Ma a, mug,

ATTORNEYS I Patented Aug. 18, 1942 nanvroaonn 2,293,246 vuacamzan FIBER. BACKING BELT Home a. Fay, Willoughby, Ohio Application August 26, 1941, Serial No. 408,289 (Cl. 154-46) 4Clalms.

This invention relates to reinforced vulcanized fiber and to a method of making the same.

In Carlton Patent No. 1,686,898 and Stratford Patent No. 1,684,748, there is disclosed an abrad- I have discovered that by incorporating flexible glass fibers in or inserting them' between the plies or layers of the stock used for making vulcanized fiber, that I can make backing belts increase the resistance of the belt, when thus used, to the stretching or elongation imparted to the vulcanized fiber as the result of the abrading action, and also increase the life of the vulcanized ing or surfacing disk having a backing sheet 5 fiber belt under conditions resulting from the made of hydrated or hydrolyzed cellulose, comabrading operation. mercially known as vulcanized fiber. This ma- These fibers are inserted between the layers terial is made bytr'eating cellulose with a ma of the stock in such a manner that they are terial capable of partially dissolving the cellulose, spaced transversely of the stock and extend longisuch for example as zinc chloride. '10 "tudinally thereof, and although a series of paral- In manufacturing this material, old cotton lel unconnected fibers may be employed, the inrags are commonly employed as the raw material, sertion of such longitudinal fibers is facilitated since such rags consist of almost pure cellulose, by incorporating them in a netting consisting of these being pulped and formed into sheets .in the such fibers and a series of transverse fibers interordinary manner. The sheets are then passed woven therewith. Since the transverse fibers in through azinc chloride solution which causes the that event are used merely to hold the longipartial solution of the fibers, the outside of each tudinal fibers in properly spaced relation, and individual fiber being probably partially dissuch transverse fibers do not contribute to insolve'd, producing a gelatinous, and more or less creasing the tensile strength for endless belt puradhesive, coating on each fiber. The sheets thus poses, the transverse fibers need not be spaced as treated are then again passed through rolls to closely a the lon itu in l fi rsremove the excess zinc chloride and to compress Instead of a coarsely woven netting, as dethe fibers tightly together. Final traces of zinc scribed, coarsely woven glass cloth, such as is now chloride are then removed, as by washing the available in the market, may be employed. sheets in water, after which the sheets are The fibers, netti r cloth may be p a d n hardened and dried. Reagents, other than zinc the sheets before they are passed through the chloride, may be employed, provided that they zinc chloride solution or after they have passed also partially gelatinize the fibers to produce a through such Solu i n n t first case, h chemical and mechanical adhesion between the spaces or openings between the fibers are sumfibers during the treatment which is far more ciently large that the fibers do not appreciably eifective in cementing the entire structure tointerfere with the treatment of the sheets by the gether than merely the ordinary mechanical adzinc chloride solution, and in both cases, the hesion secured through pressure in the ordinary la fi er e n in y Way attacked or altered paper stock. by such solution.

The result of this treatment of the material The spacing of the fibers will depend, of course, is to greatly increase the strength, the density on the .thickness or diameter thereof. Since, and the rigidity, and to lower the porosity while however, fibers made of glass have a tensile producing a structure which has littlev or no strength approximating that of steel wire of the tendency to split or curl, and when used in the same diameter, fibers of less than .001" have form of a backing for surfacing disks, the tensile been found to be satisfactory for most purposes. strength of the product is ordinarily sufiicient Glass fibers of a thickness of .001 or less can be for most abrasive purposes. flexed ,without breaking, and where the term Ithas been proposed to use this vulcanized "flexible" is used herein, it is to be understood fiber as a backing i th f r of dless belts that the term comprises fibers of these dimenfor surfacing or abrading purposes, but it has 4 Sions. been found that such belts, when in use, are In the accompanying drawing, I have illusordinarily subjected to longitudinal stresses .trated more r l ss d a ra atic y one m thod which exceed the tensile strength of vulcanized w c y be p e for co po ating the fiber, and which cause the belts. to stretch or glass fibers, netting or cloth in the stock during, become elongated. the manufacture of the vulcanized fiber.

In said drawing:

Fig. 1 is an illustration in elevation ofthe process;

Fig. 2 is an illustration in plan of the process;

for abrading material, in which the glass fibers n Fig. 3 is a fragmentary cross-sectional view of a sheet of reinforced vulcanized fiber made according to the process, as illustrated in Figs. 1 and 2; and

Fig. 4 is a view similar to Fig. 3, but showing a modified form of product.

Referring more particularly to Figs. 1 and 2, i represents a ply or layer of paper stock after having been pulped, and as it comes from a Fourdrinier machine.

The layer I proceeds through a tank 2 containing zinc chloride solution, but before passing through such solution, a-netting 3 of glass fibers my copending application, Serial No. 259,693, filed is applied to the upper surface of the ply or layer 7 I, such netting consisting of longitudinal fibers 4 which are relatively closely spaced and transverse fibers 5 which are spaced farther apart than thefibers 4.

A second ply or layer 6 of pulped paper stock from another Fourdrinier machine is passed through a tank 1 containing zinc chloride solution, and this ply, after being treated with the solution, is then laid upon the upper surface of the ply I, so that the netting 3 of glass fibers is interposed between the plies.

The plies l and 6, with the netting 3 of glass fibers interposed therebetween is then subjected to the usual treatment for manufacturing vulcanized fiber, which includes passage through rolls 8 to remove the excess zinc chloride and compress the fibers tightly together, washing of the sheets in water, hardening and drying. During this treatment, the glass fibers are not in any way affected.

The vulcanized fiber, thus made, may be formed into endless belts by any of the usual methods used in the formation of such belts, and such belts may then have abrasive materialapplied thereto, as by the methods described in the aforesaid Carlton and Stratford patents. A transverse section through such a belt is shown in Fig. '3.

The product shown in Fig. 4 is made by first laying the glass fiber netting on a Fourdrinier screen and then spreading the stock from which the vulcanized fiber is made on such netting, the fibers of such stock enveloping or partially enveloping the fibers of such netting. The only difference between this product and that shown in Fig. 3 is that the glass fibers are on the outside of or closely adjacent to the outer surface of the vulcanized fiber sheet instead of being interposed between plies thereof. In the product shown in Fig. 4, the abrasive material is preferably applied to the upper surface.

Backing belts for abrading material, endless belts and other articles made from the products which have been described are characterized by high tensile strength, "and are to a great extent capable of resisting stretching and elongation. Backing belts for abrading material, in particular, when made from such products are characterized by increased resistance to the stretching or elongation imparted to the vulcanized belt as a result of the abrading action, as well as an increased life under conditions resulting from the abrading operation.

March 3, 1939.

Other forms may be employed embodying the features of my-invention instead of the one here explained, change being made in the form or construction, provided the" elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by my preferred method or by others embodying steps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention:

1. As a new article of manufacture, a backing belt for abrading material, said belt consisting of layers of vulcanized cellulose fiber and flexible glass fibers, said flexible glass fibers being embedded in and extending generally longitudinally through the vulcanized fiber layers, said glass fibers increasing the resistance of the belt, when over about .001" in thickness and being embedded in and extending generally longitudinally through the vulcanized fiber layers, said glass fibers increasing the resistance of the belt, when thus used, to the stretching or elongation imparted to the vulcanized fiber as the result of the abrading action, said glass fibers also increasing the life or the vulcanized fiber belt under conditions resulting from the abrading operation.

3. As a new article of manufacture, a backing belt for abrading material, said belt consisting of a plurality of layers of vulcanized cellulose fiber and a layer of flexible glass fibers embedded therebetween and extending generally longitudinally of the belt, said glass fibers increasing the resistance of the belt, when thus used, to the stretching or elongation imparted to the vulcanized fiber as the result of the abrading action, said glass fibers also increasing the life of the vulcanized fiber belt under conditions resulting from the abrading operation.

4. As a new article of manufacture, a backing belt for abrading material, said belt consisting of a layer of vulcanized cellulose fiber and a layer of flexible glass fibers embedded in one surface thereof and extending generally longitudinally of the vulcanized fiber layer, said glass fibers increasing the resistance of the belt, when thus used, to the stretching or elongation imparted to the vulcanized fiber as the result of the abrading action, said glass fibers also increasing the life of the vulcanized fiber belt under conditions resulting from the abrading operation.

HORACE B. FAY. 

